AP1000®Plant Passive Safety Systems and Timeline for Station Blackout @ Westinghouse Simply Safer- Naturally The Westinghouse AP1000® Pressurized Water Reactor (PWR) is simply more advanced than other nuclear power plant technologies available today in the worldwide commercial marketplace. Today, Westinghouse is more focused than ever on making clean, safe and reliable energy possible and practical. Safety is always the number one priority of the AP1000 plant. During a station blackout, or loss of all electrical power, the AP1000 plant's passive safety system shuts down the reactor automatically, with no need for human intervention for up to 72 hours. The AP1000 plant's truly innovative technology harnesses natural forces like gravity, convection and condensation to achieve safe shutdown of the reactor. In 2018 and early 2019, 4 AP1000 units entered commercial operation, marking the first successful deployment of Generation III+ reactors. They then went on to achieve record-breaking first cycle and first refuelling outage performance. The AP1000 plant is now recognized as the most advanced, proven nuclear technology available, delivering safe, clean, reliable power. Simply More Advanced PCS GRAVITY DRAIN • AC power is not required WATERTANK for safe shutdown NATURAL CONVECTION AIR DISCHARGE • Core cooling provided for long-term safe shutdown state: IN-CONTAINMENT REFUELING WATER 72 hours without operator action STORAGE TANK ® • The AP1000 Pressurized Water Reactor OUTSIDE COOLING (PWR) is designed so that the core stays AIR INTAKE inside of the reactor vessel during a severe accident ...... ,- \ I I I SHIELD • The AP1000 PWR incorporates 60 years .a, .a, BUILDING of operational lessons-learned t t t INTERNAL CONDENSATIONAND STEEL NATURAL RECIRCULATION CONTAINMENT VESSEL • After 72 hours with some operator AIR actions to transfer water, core cooling and BAFFLE containment cooling are maintained indefinitely • The AP1000 PWR Spent Fuel Pool Cooling System is capable of providing cooling for spent reactor fuel indefinitely, with minimal need for operator action TRANSFER OF REACTOR DECAY HEAT TO OUTSIDE AIR Station 1 minute Controlrods are inserted into 2 minutes The steam generator water 2 hours 3 hours The cooling water in the 5 hours The passive heat exchanger 6 hours The instrumentation monitoring 6-7 hours The steam generated by the > 7 hours As the steam from the 36 hours Safe The operatorsstart the ancillary Diesel fuel is replenishedin the the reactorcore, terminating the level decreasesand spent fuelpool begins to has transferredenough decay system detects the need for in-containment tank transfers in-containment tank diesel generators to providepower ancillary generators ifpower is not Blackout Occurs: fission process and shutting activatesthe Passive Core boil. Decay heat from the heat fromthe reactor to the containment cooling and opens the decay heat to the steel of transfersdecay heat to the Shutdown forpost-accident monitoring, water restored to the site, to maintain the m Loss of offsitepower Cooling System. spent fuelis transferred in-containment tank that the valves to startcooling water the containment vessel makeuppumps and main control ancillaryfunctions . down the reactor. The reactor steel containment vessel, the Condition occurs.At the same time, core continues to produce decay from the water to thesteam. water inside the in-containment flow(Passive Containment throughcondensation of the steam condenses back to roomlighting, the standby diesel heat that needs to be removed Natural circulation Any evaporated water is tank begins to boil. Steam is Cooling System). steam. The water cooling the water and is redirectedback Water from other available generatorsfail to start, by cooling. flowis started replaced from a supply located produced insideof the steel containment vessel to the in-containment tank for Water makeup pumps are used to sources, including on-site tanks, resultingin a automatically in the adjacent cask washdown containment vessel. Water in the containment removes decay heat continued use in removing transferwater fromthe ancillary sea water, or other off-sitewater station blackout. Active pumping of cooling water because of density pit, which is gravity-fed to cooling tank, located on the throughevaporation. decay heat fromthe reactor water storagetank to the passive suppliesis transferredto either throughthe spent fuel pool stops differencesbetween thespent fuel pool. roof of the shield building, core. This cooling cycle containment coolingwater storage the ancillarywater storage tank or l has safe due to loss of power. The used the cold reactor coolant in Reactor decay heat has decreased to automaticaly drains through Natural convection airflow continues indefinitely. The reactor reached shutdown tank to maintain water cooling of the safety-related makeup water fuel in the spent fuelpool the passive heat exchanger gravityand cools the top passing throughthe shield the containment. flanged connection in the yard. continuesto transferdecay heat and the hot fuel in the one percent of fullpower. and sides of the steel buildingpromotes the condition without operator action and Portable equipment could be used to the pool of water, causing the reactorcore. containment vessel. water cooling of without the use of active AC power sources, These pumps also transferwater to continue cooling of the water to heat up. the containment. using passive cooling. Reactor decay heat from the ancillarywater storage containment vessel and generation is one half of one percent tank to the spent fuel pool to the spent fuelpool. of fullpower. continue its cooling of the spent fuel. The operatorcan continue to transfer water to maintain containment and spent fuel pool cooling indefinitely ------------- Reactor decay heat is slight/y more 1 than one thirdof one percent - of futI power. 1 PCS GRAVITY DRAIN WATER TANK FIRE WATER FIRE WATER/ CLEARWELL STORAGE TANK STORAGE TANK IN-CONTAINMENT • PCS TANK IN-CONTAINMENT REFUELING WATER (Pccwsn- �-- REFUELING WATER STORAGE TANK CONTAINMENT CONDENSATE REACTOR DECAYHE AT GENERATION STORAGE TANK SERVICE WATER CONTAINMENT COOLING TANK 1%AFTER COOLING TOWERS FIRE PROTECTION r (PCCWST) I ••DIESEL GENERATOR FUEL WATERTANKS OIL STORAGE TANKS I FEEDWATER SHIEL□ HOURS LINE BUILDING CONDENSATE DIESEL GENERATOR STORAGE TANK BUILDING PASSIVE CONTAINMENT COOLING AIR ■ ANCILLARYWATER STORAGE TANK BAFFLE RCP BORIC ACI□ - ,' "STORAGE TANK TIME AFTER m.JP (SECONDS} REACTOR VESSEL , ,n�. □EMINERALIZED WATER . V • STORAGE TANK . POOL '. ANCILLARYDIESEL '"'"' '"" j • - GENERATORS AP1000 DECAY HEAT CURVE O • 7 DAYS 3D VERSION OF PXS AND REACTOR COOLANT SYSTEM SPENT FUEL POOL WATER SOURCES FOR 7 DAYS NATURAL CIRCULATION & DECAY HEAT TRANSFER TRANSFER OF REACTOR DECAY HEAT TO OUTSIDE AIR EMERGENCY COOLING WATER TANK LOCATIONS AP1000 TANK LAYOUT SIMPLYELECTRIC ™ Follow us on: lm,rl www.westinghousenuclear.com AP1000 and the AP1000 logo are trademarks or registered trademarks of Westinghouse Electric Company LLC, its subsidiaries and/or its affiliates in the United States. These marks may also be used and/or registered in other countries throughout the world. All rights reserved. Unauthorized use is strictly prohibited. © 2021 Westinghouse Electric Company LLC. All rights reserved. Westinghouse Graphic Services & Identity: 88473A_rev0_1 0/11_ 10M .